The present invention relates to an apparatus for continuous steaming and dimensional stabilization of fabrics in the form of continuous webs.
At present, apparatuses are known and used for continuously performing the steaming, the relaxation, the shrinkage and the dimensional stabilization of fabrics in general. Under the generic term "fabrics", both fabrics of weft-warp type and knitted fabrics, as well as even non-woven fabric made from any materials of natural, man-made and synthetic origin, are to be understood.
The apparatuses known from the prior art have the purpose of determining a stabilization of the fabrics without applying any cross and/or longitudinal (i.e., in the machine direction) stresses to the material under treatment.
These apparatuses essentially are constituted by a conveyor belt and a tunnel inside which the fabric is caused to run through. The conveyor belt is arranged as a closed ring and has a partially open surface structure, such as constituted by a net, so as to be permeable after receiving the fabric to be treated.
The tunnel is assimilable to a steaming tank through which the fabric supporting conveyor belt runs. Under said conveyor belt, a steam delivering device, and over it a roof, or, anyway, a heated condensation preventing cover connected with a sucking hood with a vent fan are respectively provided. The vent fan also intakes the steam which leaves the tunnel through the inlet and outlet openings of the latter, through which the conveyor belt and the fabric web run, together with a certain air amount from the working premises.
Although they effectively treat the fabric and supply it with optimal, natural, stress-free relaxation and shrinkage effects, such a kind of apparatuses known from the prior art unfortunately display the following drawbacks.
High steam consumption, because the tunnel must be constantly kept filled with steam and in the mean time there is a continuous escape of steam from said tunnel inlet and outlet openings. In fact, the steam excess is continuously sucked, together with a certain air amount from the working premises, by the suction hood which is installed over the tunnel and is provided with a vent fan.
Continuous steam and air venting to the surrounding atmosphere, with considerably high energy consumption and waste for the treatment and the heating of steam and air from the working premises.
Treatment of fabric inside the tunnel with a mixed atmosphere of air and steam, with the treatment temperature being consequently limited at 100.degree. C. or slightly higher temperatures, and incomplete and optimal dimensional stabilization of the fabric.